1. Field of the Invention
The present invention relates to a highly efficient all-optical switching system and the method thereof. With the method provided by the present invention the transmission rate of the optical fiber communication network increases a lot.
2. Related Art
Along with the rapid growth of the Internet and mobile phone users, the demand of the data transmission rate and the need of the broad-band communication are getting higher and higher. It is a trend in the future to use the optical fiber network with the light as a medium of transmission. Although the data on the optical fiber network is transmitted in the form of light, a router of the optical fiber network could only routes electrical signals. Thus when the optical data is transmitted to a routing point, it has to be converted into electrical data first. After the electrical data is routed by the electrical router (switching system), it has to be converted back into the optical data and to be transmitted by the optical fiber network subsequently. Such xe2x80x9coptical data-electrical data-optical dataxe2x80x9d (O-E-O) routing mode not only costs higher but also reduces the transmission rate of the optical data and becomes a bottle-neck of the transmission rate of the optical fiber network.
There are several conventional all-optical switching devices (optical data-optical data-optical data, O-O-O) of communication network as follows.
1. A device which utilizes movable mirrors to do the light switching (refer to U.S. Pat. No. 4,580,873);
2. A device which utilizes refraction of air bubbles to do the light switching (refer to U.S. Pat. No. 4,988,157);
3. A device which utilizes movable fibers and the principle of magnetic field to do the light switching (refer to U.S. Pat. No. 6,169,826);
4. A device which utilizes movable fibers and the principle of a spiral motor to do the light switching (refer to ROC Patent Publication Nos. 296,806 and 289,441);
3. The Disadvantages of the Prior Arts
1. To Use the Movable Mirrors to Do the Light Switching
This is a kind of mechanical rotating apparatus whose rotating shaft of the mirrors might affect the light signal transmission with wrong rotating angles caused by mechanical fatigue. It is hard to detect if there is anything wrong with the rotating angle of the mirrors, and the cost of maintenance is high. Besides, a nxc3x97m switching structure (n input light signals and m output light signals) needs nxc3x97m mirrors. Since there is a limit to reduce the mirrors in size, the system is huge. The area of a 64xc3x9764 switching structure will be 256 times of that of the 4xc3x974 switching structure in size.
2. To Use the Refraction of Air Bubbles to Do the Light Switching
It is similar to the principle of the mirror refraction mentioned above, but it is liquid bubble used for refraction in this case. When the light passes the liquid, it is refracted by the bubble generated from the liquid. The liquid in the envelopes will be vaporized after a long time usage or the tiny dust will enter the envelopes due to the untight envelopes which might affect the generated bubbles and cause inaccurate refraction angle. It will be hard to refill the envelopes after the liquid is vaporized if the envelopes are too tight. Also it is needed to detect the status of the liquid often. The cost for maintenance is high.
3. To Use the Movable Fibers and the Principle of the Magnetic Field to Do the Light Switching
This method only applied to one-dimensional switching device (1xc3x97N) and is actually hard to apply to two-dimensional switching device (Nxc3x97M).
4. To Use the Movable Fibers and the Principle of the Spiral Motor to Do the Light Switching
This method only applied to one-dimensional switching device (1xc3x97N) and is actually hard to apply to two-dimensional switching device (Nxc3x97M).
The most serious disadvantage of the above mentioned four methods is that they can not be commercially mass produced. There are some serious problems of the reliability and the cost to be resolved.
This invention utilizes xe2x80x9coptical data-optical data-optical dataxe2x80x9d (O-O-O) switching mode to switch the light directly and to avoid the disadvantage of the low transmission rate of the conventional (O-E-O) switching system and improve the disadvantages of the conventional (O-O-O) switching system.
This invention is to provide a feasible, highly-efficient all-optical switching system and a method thereof. To use the method provided by this invention will increase the transmission rate of the optical fiber communication network.
This invention provides an all-optical switching system and its method. The system comprises: N 1xc3x97M splitters for receiving N sets of optical data I1, I2, . . . , INxe2x88x921, IN. Said N splitters split said N sets of optical data into M sets of optical data respectively and generate a Nxc3x97M matrix D of optical data as follows:   D  =      [                                        D                          1              ,              1                                                            D                          1              ,              2                                                ⋯                                      D                          1              ,                              M                -                1                                                                          D                          1              ,              M                                                                        D                          2              ,              1                                                            D                          2              ,              2                                                ⋯                                      D                          2              ,                              M                -                1                                                                          D                          2              ,              M                                                            ⋮                          ⋮                          ⋰                          ⋮                          ⋮                                                  D                                          N                -                1                            ,              1                                                            D                                          N                -                1                            ,              2                                                ⋯                                      D                                          N                -                1                            ,                              M                -                1                                                                          D                                          N                -                1                            ,              M                                                                        D                          N              ,              1                                                            D                          N              ,              2                                                ⋯                                      D                          N              ,                              M                -                1                                                                          D                          N              ,              M                                            ]  
wherein N and M are integers, the M sets of optical data D1,1, D1,2, . . . , D1,Mxe2x88x921, D1,M are generated by the first 1xc3x97M splitter by splitting the first optical data I1, and D1,1=D1,2= . . . =D1,Mxe2x88x921=D1,M=I1. On the analogy of this, an Nxc3x97M matrix switching structure to receive the Nxc3x97M matrix D of optical data generated by the splitters and receive another driving signals matrix S simultaneously as follows:   S  =      [                                        S                          1              ,              1                                                            S                          1              ,              2                                                ⋯                                      S                          1              ,                              M                -                1                                                                          S                          1              ,              M                                                                        S                          2              ,              1                                                            S                          2              ,              2                                                ⋯                                      S                          2              ,                              M                -                1                                                                          S                          2              ,              M                                                            ⋮                          ⋮                          ⋰                          ⋮                          ⋮                                                  S                                          N                -                1                            ,              1                                                            S                                          N                -                1                            ,              2                                                ⋯                                      S                                          N                -                1                            ,                              M                -                1                                                                          S                                          N                -                1                            ,              M                                                                        S                          N              ,              1                                                            S                          N              ,              2                                                ⋯                                      S                          N              ,                              M                -                1                                                                          S                          N              ,              M                                            ]  
and generates an Nxc3x97M matrix Dxe2x80x2 of optical data as follows:       D    xe2x80x2    =      [                                        D                          1              ,              1                        xe2x80x2                                                D                          1              ,              2                        xe2x80x2                                    ⋯                                      D                          1              ,                              M                -                1                                      xe2x80x2                                                D                          1              ,              M                        xe2x80x2                                                            D                          2              ,              1                        xe2x80x2                                                D                          2              ,              2                        xe2x80x2                                    ⋯                                      D                          2              ,                              M                -                1                                      xe2x80x2                                                D                          2              ,              M                        xe2x80x2                                                ⋮                          ⋮                          ⋰                          ⋮                          ⋮                                                  D                                          N                -                1                            ,              1                        xe2x80x2                                                D                                          N                -                1                            ,              2                        xe2x80x2                                    ⋯                                      D                                          N                -                1                            ,                              M                -                1                                      xe2x80x2                                                D                                          N                -                1                            ,              M                        xe2x80x2                                                            D                          N              ,              1                        xe2x80x2                                                D                          N              ,              2                        xe2x80x2                                    ⋯                                      D                          N              ,                              M                -                1                                      xe2x80x2                                                D                          N              ,              M                        xe2x80x2                                ]  
M sets of Nxc3x971 combiners receive the Nxc3x97M matrix Dxe2x80x2 of optical data output from the Nxc3x97M matrix switching structure. Said M sets of combiners combine N sets of optical data respectively to generate M sets of optical data O1, O2, . . . , OMxe2x88x921, OM, wherein the first output optical data O1 is generated by the first combiner after combining N sets of optical data Dxe2x80x21,1, Dxe2x80x22,1, . . . , Dxe2x80x2Nxe2x88x921,1, Dxe2x80x2N,1, on the analogy of this.
In order to make the technical contents and characteristics easier to be understood, the preferred embodiment is introduced with the brief description of the drawings as follows.